Electro-optical device, projection-type display device, electronic device, and manufacturing method of the electro-optical device

ABSTRACT

An electro-optical device including a pixel electrode provided over one side of a substrate, a conductive layer provided between the substrate and the pixel electrode, and a relay electrode provided between the substrate and the conductive layer. The conductive layer includes a first conduction section protruding toward the pixel electrode and a second conduction section protruding toward the relay electrode. The first conduction section is cylindrical-shape having an upper surface which is attached to the pixel electrode, and having a side surface sloping from the upper surface. The pixel electrode is electrically connected to the relay electrode through the conduction section.

The present application is a continuation application of U.S. patentapplication Ser. No. 14/794,735 filed on Jul. 8, 2015, which is acontinuation application of U.S. patent Ser. No. 13/551,828 filed onJul. 18, 2012, which claims priority from Japanese Patent ApplicationNo. 2011-159619 filed on Jul. 21, 2011, which are expressly incorporatedby reference herein.

BACKGROUND

1. Technical Field

The present invention relates to an electro-optical device including aliquid crystal device, a projection-type display device, and anelectronic device, and more particularly to a peripheral configurationof pixel electrodes of the electro-optical device.

2. Related Art

The pixels with pixel electrodes are arranged in the matrix on anelement substrate for use in the electro-optical device, such as aliquid crystal device and an organic electroluminescence device, and thepixel electrode is electrically connected to a conductive layer beneaththe pixel electrode in the downward direction, through a contact holeformed in an insulating film (refer to JPA-2006-317903).

The contact hole in this electro-optical device is large in horizontalsize, and the electro-optical device decreases in display grade. Forexample, the contact hole in a liquid crystal device is so large inhorizontal size that a pixel electrode has a large depression andelevation on the surface. This prevents an oriented film from beingformed in a suitable manner. Furthermore, in a transmission-type liquidcrystal device, an amount of display light decreases because lightcannot pass through the contact hole. Furthermore, an area of thedepression and elevation does not contribute to display, because thereflection direction of light is in disorder there, when the pixelelectrode has the large depression and elevation on the surface in areflection-type liquid crystal device.

On the other hand, a configuration is commonly employed that buries aplug in a contact hole in an inter-layer insulating film, andelectrically connects the pixel electrode and an electrode beneath thepixel electrode (that is, in the downward direction), through this plugburied in the contact hole in the inter-layer insulating film (refer toJP-A-2011-64849). With this configuration, the contact hole is madesmaller in horizontal size, thereby preventing the large depression andelevation from being formed on the surface of the pixel electrode.

However, in the conducting structure that uses the plug, it is necessaryto additionally prepare a metal material, which is not in common use forthe electro-optical device, such as tungsten, in order to form the plug.This increases the manufacturing cost. Furthermore, it is necessary toperform a step of sputtering metal to thicken a metal film for the plugand a step of smoothing an inter-layer insulating film by a chemicalmachinery polishing method, until the contact hole is filled. Thesputtering step of these steps decreases productivity because it takestoo much time to sputter metal to thicken the metal film for the plug.

SUMMARY

An advantage of some aspects of the invention is to provide anelectro-optical device that has a conduction portion of a pixelelectrode, not occupying a large area, formed by using a film formed forother purposes, and therefore has not a large depression and elevationon a surface of the pixel electrode, a projection-type display device,and an electronic device.

According to an aspect of the invention, there is provided a pluralityof pixel electrodes provided over one side of a substrate, a firstinsulating film, provided between the substrate and the plurality ofpixel electrodes, including pillar-shaped protrusions protruding towardthe pixel electrodes in positions overlapping the pixel electrodes whenviewed from above, a conductive layer, provided between the firstinsulating film and the pixel electrodes, including a conduction sectionoverlapping highest surfaces of the pillar-shaped protrusions whenviewed from above, and a second insulating film, provided between theconductive layer and the pixel electrodes, exposing one side of theconduction section, the one side in the direction of the pixelelectrode, wherein the pixel electrodes are deposited on one side of thesecond insulating film, the one side in the direction of the pixelelectrode, thereby resulting in the pixel electrode being electricallyconnected to the conduction section.

According to another aspect of the invention, there is provided a methodof manufacturing an electro-optical device including forming a firstinsulating film over one side of a substrate, forming a pillar-shapedprotrusion protruding upward on the first insulating film by partlyetching a surface of the first insulating film, forming a conductivelayer on the first insulating film including an area for forming thepillar-shaped protrusion, forming a second insulating film on theconductive layer, exposing as a conduction section a portion overlappingthe highest surface of the pillar-shaped protrusion when viewed fromabove, in the conductive layer, by removing the second insulating filmin the downward direction, and forming a pixel electrode on the secondinsulating film including the exposed portion of the conduction section.

The pillar-shaped protrusions, protruding toward the pixel electrodes ina position overlapping the pixel electrodes are formed on the firstinsulating film provided between the pixel electrodes and the substrate.These highest surfaces of the pillar-shaped protrusions overlap theconduction section of the conductive layer when viewed from above.Furthermore, the second insulating film is provided between theconductive layer and the pixel electrode, but the conduction section isexposed on the surface of the second insulating film in the direction ofthe pixel electrode. For this reason, the pixel electrodes areelectrically connected to the conduction section, when the pixelelectrodes are laminated on the second insulating film. For this reason,a contact portion is smaller in horizontal size, and the pixel electrodedoes not have a large depression and elevation on the surface, comparedto the structure that connects the pixel electrode and the conductivelayer by using a contact hole formed in the insulating film.Furthermore, the pixel electrode is electrically connected by using afilm formed for other purposes in the electro-optical device, such as aconductive layer and an insulating film, and special metal for a plugdoes not need to be thickly deposited.

The surface of the conduction section in the direction of the pixelelectrode and the surface of the second insulating film in the directionof the pixel electrode may make up one plane surface in succession. Inthis configuration, the pixel electrode is made to be formed on theplane surface.

The electro-optical device may further include a capacity electrodelayer, provided between the conductive layer and the substrate, and adielectric layer, provided between the capacity electrode layer and theconductive layer, with a storage capacitance being formed from thecapacity electrode layer, the dielectric layer, and the conductivelayer. That is, the pixel electrode may be electrically connected byusing an electrode layer (the conductive layer) making up the storagecapacitance.

In the electro-optical device, the first insulating film may be providedbetween the capacity electrode layer and the conductive layer, and anopening may be provided in an area where the capacity electrode layerand the conductive layer overlap each other when viewed from above. Inthis configuration, although the dielectric layer is thin, the shortcircuit between the highest portion of the first insulating film and thecapacity electrode layer may be prevented by the first insulating film.

In the electro-optical device, in the pixel electrodes, the conductivelayer and the capacity electrode layer may be provided in an area thatoverlaps an area between the adjacent pixel electrodes when viewed fromabove. In this configuration, since the conductive layer is positionednearer the pixel electrode than the capacity electrode layer, liquidcrystal orientation is not disturbed by potential occurring between thepixel electrode and the capacity electrode layer.

In the electro-optical device, the pillar-shaped protrusion may beprovided in a position that overlaps the capacity electrode layer whenviewed from above. In this configuration, since the pillar-shapedprotrusion and the conduction section are provided at a high level, afilm-thick portion of the capacity electrode layer may be electricallyconnected to the pixel electrode, in an easy manner.

The electro-optical device for use in a liquid crystal device, may havea configuration that holds a liquid crystal layer between the substrateand an opposite substrate opposite to the substrate.

The electro-optical device to which an aspect of the invention isapplied may be used in a variety of display devices for a variety ofelectronic devices, such as a direct-view display device. Furthermore,the electro-optical device to which the aspect of the invention isapplied may be used in a projection-type display device. Thisprojection-type display device includes a light source unit emittinglight to be incident on the electro-optical device, and a projectionoptical system projecting light modulated by the electro-optical device.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements;

FIG. 1 is a block diagram illustrating an electrical configuration of anelectro-optical device to which an aspect of the invention is applied.

FIGS. 2A and 2B are explanatory views of a liquid crystal panel used inthe electro-optical device to which the aspect of the invention isapplied.

FIGS. 3A and 3B are explanatory views of pixels of the electro-opticaldevice to which the aspect of the invention is applied.

FIGS. 4A to 4F are explanatory views of the essential steps of amanufacturing process of the electro-optical device to which the aspectof the invention is applied.

FIGS. 5A to 5E are explanatory views of the essential steps of themanufacturing process of the electro-optical device to which the aspectof the invention is applied.

FIGS. 6A and 6B are explanatory views showing the effects of theelectro-optical device to which the aspect of the invention is applied.

FIGS. 7A and 7B are diagrams illustrating schematic configurations of aprojection-type display device to which the aspect of the invention isapplied, and an optical unit.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

The embodiments are now described with reference to the accompanyingdrawings. Among a variety of electro-optical devices, the liquid crystaldevice and a method of manufacturing the liquid crystal device aredescribed, focusing on the case where the aspect of the invention isapplied in connecting electrically a pixel electrode 9 a and a secondelectrode layer 7 a (a conductive layer). Furthermore, layers andmembers are enlarged to recognizable degrees in each of the figures, andthus vary in scale from figure to figure. Furthermore, the roles of asource and a drain are in practice interchanged when a direction ofelectrical current flowing through a pixel transistor is reversed.However, one side (a source drain area in the direction of the pixel),to which the pixel electrode is electrically connected, is defined as adrain, and the other side (a source drain area in the direction of thedata line), to which a data line is electrically connected, is definedas a source. Furthermore, when describing a layer formed on an elementsubstrate, the term ‘the upward direction’ or ‘the surface direction’ isused to mean the direction opposite to the direction in which thesubstrate body of the element substrate is positioned (the direction ofthe opposite substrate), and the term ‘the downward direction’ is usedto mean the direction in which the substrate body of the elementsubstrate is positioned (the direction opposite to the direction inwhich the opposite substrate is positioned).

Description of Electro-Optical Device (Liquid Crystal Device)

Whole Configuration

FIG. 1 is a block diagram illustrating an electrical configuration ofthe electro-optical device to which an aspect of the invention isapplied. FIG. 1 is only an electrical block diagram and thereforeschematically shows a layout, such as a direction in which a capacityelectrode layer extends.

As shown in FIG. 1, the electro-optical device 100 (a liquid crystaldevice) according to the invention includes a liquid crystal panel 100 pof a TN (Twisted Nematic) mode and a VA (Vertical Alignment) mode. Theliquid crystal panel 100 p has an image display area 10 a (a pixel area)in the middle, where a plurality of pixels 100 a are arranged in thematrix. In the liquid crystal panel 100 p, a plurality of data lines 6 aand a plurality of scan lines 3 a extend in rows and columns within theimage display area 10 a on the element substrate 10 (refer to FIGS. 2Aand 2B), which is described below, and the pixels 100 a are formed in aposition corresponding to an intersection where the data line 6 a andthe scan line 3 a cross each other. A pixel transistor 30, made from aneffect type transistor and a pixel electrode 9 a to be described below,is formed on each of the plurality of the pixels 100 a. The data line 6a is electrically connected to a source of the pixel transistor 30. Thescan line 3 a is electrically connected to a gate of the pixeltransistor 30. The pixel electrode 9 a is electrically connected to adrain of the pixel transistor 30.

A scan line drive circuit 104 and a data line drive circuit 101 areprovided outside of the image display area 10 a on the element substrate10. The data line drive circuit 101 is electrically connected to each ofdata lines 6 a and sends an image signal, received from an image processcircuit, sequentially to each of the data lines 6 a. The scan line drivecircuit 104 is electrically connected to each of scan lines 3 a andsequentially sends a scan signal to each of the scan lines 3 a.

The pixel electrode 9 a in each pixel 100 a is opposite to a commonelectrode formed on the opposite substrate 20 (refer to FIGS. 2A and 2B)to be described below, through a liquid crystal layer, and makes up theliquid crystal capacitance 50 a. Furthermore, a storage capacitance 55is added to each pixel 100 a, in parallel with the liquid crystalcapacitance 50 a, to prevent a change in an image signal retained in theliquid crystal capacitance 50 a. In the embodiment, a first electrodelayer 5 a straddling the plurality of pixels 100 a is formed as anelectrode capacity layer to make up the storage capacitance 55. In theembodiment, the first electrode layer 5 a is electrically connected to acommon potential line 5 c to which common potential Vcom is applied.

Configuration of Liquid Crystal Panel 100 p

FIGS. 2A and 2B are explanatory views of the liquid crystal panel 100 pfor use in the electro-optical device 100 to which the aspect of theinvention is applied. FIG. 2A is a top view of the liquid crystal panel100 p and elements of the liquid crystal panel 100 p, when viewed fromthe opposite substrate. FIG. 2B is a cross sectional view of the liquidcrystal panel 100 p and the elements of the liquid crystal panel 100 pcut along line IIB-IIB.

As shown in FIGS. 2A and 2B, the liquid crystal panel 100 p is made byattaching an element substrate 10 (an element substrate for use in theelectro-optical device) and the opposite substrate 20 to each other,with a given distance in between, by using a sealant 107 provided in aframe shape along the edge of the opposite substrate 20. The sealant 107is an adhesive made of a material such as a photopolymer or athermosetting resin. The sealant 107 is mixed with a gap-maintainingmaterial, such as a glass fiber or a glass bead to maintain the givendistance between the two substrates.

In this configuration, in the liquid crystal panel 100 p, the elementsubstrate 10 and the opposite substrate 20 are all in the rectangularform, and thus the image display area 10 a, as described referring toFIG. 1, is provided in the rectangular form in the near middle of theliquid crystal panel 100 p. Accordingly, the sealant 107 is provided inthe near rectangular form, and a periphery area 10 b in the nearrectangular form is provided in the picture frame between an innerperipheral line of the sealant 107 and an outer peripheral line of theimage display area 10 a. In the element substrate 10, a data line drivecircuit 101 and a plurality of terminals 102 are formed along oneoutside part of the element substrate 10, but outside of the imagedisplay area 10 a, and a scan line drive circuit 104 is formed along theother outside part adjacent to the one outside part. A flexible wiringsubstrate (not shown) is connected to the terminal 102. A variety ofpotential and a variety of signals are input to the element substrate 10through the flexible wiring substrate.

The pixel transistor 30, described referring to FIG. 1, and the pixelelectrode 9 a, electrically connected to the pixel transistor 30, areformed in the matrix on the image display area 10 a, on one side 10 s ofthe one side 10 s and other side 10 t of the element substrate 10, andan oriented film 16 is formed on the pixel electrode 9 a, in the upwarddirection. This is described below in more detail.

Furthermore, a dummy pixel electrode 9 b (refer to FIG. 2B), which wasformed at the same time as the pixel electrode 9 a, is formed in aperipheral area 10 b on one side 10 s of the element substrate 10. Thedummy pixel electrode 9 b may be electrically connected to a dummy pixeltransistor, or direct to wiring without the dummy pixel transistor beingprovided. Otherwise, the dummy pixel electrode 9 b may be in a floatingstate. In the floating state, potential is not applied to the dummypixel electrode 9 b. This dummy pixel electrode 9 b contributes toreducing height positions of both of the image display area 10 a and theperipheral area 10 b to the same level and to smoothing the surface onwhich to form an oriented film 16, when smoothing the surface on whichto form the oriented film 16 on the element substrate 10. Furthermore,disturbance of the orientation of liquid crystal molecules may beprevented in the peripheral end of the image display area 10 a, when thedummy pixel electrode 9 b is set to given potential.

A common electrode 21 is formed on one side of the opposite substrate20, that is, on the one side opposite to the element substrate 10. Anoriented film 26 is formed on the common electrode 21. The commonelectrode 21 is formed in such a manner as to straddle almost the entiresurface of the opposite substrate 20, or the plurality of the pixels 100a as a plurality of strip electrodes. Furthermore, a light-shieldinglayer 108 is formed beneath the common electrode 21, in the downwarddirection (that is, in the direction of opposing the element substrate10), on one side of the opposite substrate 20. In the embodiment, thelight-shielding layer 108 is formed on the picture frame extending alongthe outer peripheral line of the image display area 10 a, and has afunction of forming a border. At this point, the outer peripheral lineof the light-shielding layer 108 is located a given distance away fromthe inner peripheral line of the sealant 107, and thus thelight-shielding layer 108 and the sealant 107 do not overlap each other.The light-shielding layer 108 may be formed as a black matrix part in,for example, an area overlapping an inter-pixel area interposed betweenthe adjacent pixel electrodes 9 a, on the opposite substrate 20.

In this configuration of the liquid crystal panel 100 p, aninter-substrate conduction electrode 109 for electrical conductionbetween the element substrate 10 and the opposite substrate 20, isformed in an area overlapping a corner part of the opposite substrate20, outside of the sealant 107, on the element substrate 10. Theinter-substrate conduction material 109 a, including conductiveparticles, is provided on this inter-substrate conduction electrode 109,and the common electrode 21 of the opposite substrate 20 is electricallyconnected to the element substrate 10, through the inter-substrateconduction material 109 a and the inter-substrate conduction electrode109. For this reason, common potential Vcom, provided from the elementsubstrate 10, is applied to the common electrode 21. The sealant 107 isprovided along the outer peripheral line of the opposite substrate 20,in such a manner as to keep the sealant 107 in almost the same width.For this reason, the sealant 107 is in the near rectangular form.However, the sealant 107 is provided in such a manner as to pass inwardto avoid the inter-substrate conduction electrode 109 in the areaoverlapping the corner part of the opposite substrate 20, and the cornerpart of the sealant 107 is in the form of an arc.

In this configuration, the electro-optical device 100 may make up atransmission-type liquid crystal device, when the pixel electrode 9 aand the common electrode 21 are formed using a translucent conductinglayer such as an ITO (Indium Tin Oxide) layer and an IZO (Indium ZincOxide) layer. In contrast, the electro-optical device 100 may make up areflection-type liquid crystal device, when the common electrode 21 isformed using the translucent conducting layer such as the ITO layer andthe IZO layer, and the pixel electrode 9 a is formed using a reflectiveconducting layer such as an aluminum layer. In the case where theelectro-optical device 100 is a reflection type, incident light from theopposite substrate 20 is modulated to display an image while it reflectsoff the element substrate 10 and is emitted. In the case where theelectro-optical device 100 is a transmission type, incident light fromone of the element substrate 10 and the opposite substrate 20 ismodulated to display an image while the incident light penetrates theother and is emitted.

The electro-optical device 100 may serve as a color display device foran electronic device such as a mobile computer, or a portable telephone.In this case, a color filter (not shown) and a protective film areformed on the opposite substrate 20. Furthermore, in the electro-opticaldevice 100, a phase difference film, a polarizing plate and others areprovided in a given direction with respect to the liquid crystal panel100 p, separately depending on a kind of a liquid crystal layer 50 inuse, a normal white mode and a normal black mode. In addition, theelectro-optical device 100 may serve as a light valve for RGB in aprojection-type display device (a liquid crystal projector), which isdescribed below. In this case, a color filter isn't formed, because eachlight of the colors, which were separated through a dichroic mirror forRGB color separation, is made to be incident on each of theelectro-optical devices 100 for RGB, as the incident light.

In this embodiment, the electro-optical device 100 is described,focusing on the case where the electro-optical device 100 is atransmission-type liquid crystal device that is served as the lightvalve for RGB, in the projection-type display device to be describedbelow, and incident light from the opposite substrate 20 penetrates theelement substrate 10 and is emitted. Furthermore, in the embodiment, theelectro-optical device 100 is described, focusing on a case where theelectro-optical device 100 includes a liquid crystal panel 100 p of VAmode that uses nematic liquid crystal compound with negative dielectricanisotropy, as a liquid crystal layer 50.

Specific Configuration of Pixel

FIGS. 3A and 3B are explanatory views of the pixels of theelectro-optical device 100 to which the aspect of the invention isapplied. FIG. 3A is a top view of the adjacent pixels in the elementsubstrate 10. FIG. 3B is a cross sectional view of the electro-opticaldevice 100 cut in a position corresponding to line IIIB-IIIB in FIG. 3A.In FIG. 3A, the following areas are indicated by the correspondinglines.

A scan line 3 a is indicated by a thick solid line. A semiconductorlayer 1 a is indicated by a thin short dotted line. The data line 6 aand a drain electrode 6 b are indicated by an alternate long and shortdash line. The first electrode layer 5 a and a relay electrode 5 b areindicated by a long thin dotted line. The second electrode layer 7 a isindicated by a chain double-dashed line. The pixel electrode 9 a isindicated by a thick short dotted line.

As shown in FIG. 3A, a pixel electrode 9 a, rectangular in shape, isformed on each of the pixels 100 a, and data lines 6 a and scan lines 3a are formed along an area overlapping an inter-pixel area 10 finterposed between the adjacent pixel electrodes 9 a, in the elementsubstrate 10. More specifically, the scan line 3 a extends along an areaoverlapping a first inter-pixel area 10 g extending in the firstdirection (in the X direction), and the data line 6 a extends along anarea overlapping a second inter-pixel area 10 h extending in the seconddirection (in the Y direction), on an inter-pixel area 10 f. Each of thedata line 6 a and the scan line 3 a extends in the straight line, andthe pixel transistor 30 is formed in an area where the data line 6 a andthe scan line 3 a intersect. As described referring to FIG. 1, the firstelectrode layer 5 a (a capacity electrode layer) is formed on theelement substrate 10, in such a manner that the first electrode layer 5a overlaps the data line 6 a.

As shown in FIGS. 3A and 3B, the element substrate 10 includes asubstrate body 10 w of translucency, such as a quartz substrate and aglass substrate, a pixel electrode 9 a formed in the direction of theliquid crystal layer 50 over the substrate body 10 w of (upward from oneside 10S of the substrate body 10 w), pixel transistor 30 for pixelswitching, and an oriented film 16, as main components. The oppositesubstrate 20 includes a substrate body 20 w of translucency, such as aquartz substrate and a glass substrate, the common electrode 21, formedon a surface of the substrate body 20 w in the direction of a liquidcrystal layer 50 (on the one side opposite to the element substrate 10),and an oriented film 26, as main elements.

The scan line 3 a is formed on one side of the substrate body 10 w, froma conducting layer such as a conductive polysilicon film, a metalsilicide film, a metal film, or metal film chemical compound, on theelement substrate 10. In the embodiment, the scan line 3 a may include alight shielding conductive film such as tungsten silicide (WSi_(x)), andfunctions as a light shielding film for a pixel transistor 30. In theembodiment, the scan line 3 a is made from tungsten silicide,approximately 200 nm in thickness. An insulating film, such as a siliconoxide film, may be provided between the substrate body 10 w and the scanline 3 a.

An insulating film 12, such as a silicon oxide film, is formed on thescan line 3 a, in the upward direction, and the pixel transistor 30having the semiconductor layer 1 a is formed on the surface of theinsulating layer 12, on the one side 10 s of the substrate body 10 w. Inthe embodiment, the insulating layer 12 has, for example, a two-layerstructure which is composed of a silicon oxide film formed by a lowpressure CVD method of using tetraethoxysilane(Si(OC₂H₅)₄), or by aplasma CVD method of using tetraethoxysilane and oxygen gas, and asilicon oxide film (a HTO (High Temperature Oxide) film) formed by ahigh temperature CVD method.

The pixel transistor 30 includes the semiconductor layer 1 a and a gateelectrode 3 c. The semiconductor layer 1 a faces the long side directionin the extension direction of the scan line 3 a in an intersection areawhere the scan line 3 a and the data line 6 a intersect. The gateelectrode 3 c extends in the direction perpendicular to the lengthwisedirection of the semiconductor layer 1 a, and overlaps the middle partof the semiconductor layer 1 a in the lengthwise direction. Furthermore,the pixel transistor 30 includes a gate insulating layer 2 oftranslucency between the semiconductor layer 1 a and the gate electrode3 c. The semiconductor layer 1 a includes a channel area 1 g facing agate electrode 3 c through the gate insulating layer 2, and includes asource area 1 b and a drain area 1 c next to both sides of the channelarea 1 g, respectively. In the embodiment, the pixel transistor 30 hasan LDD structure. Therefore, the source area 1 b and drain area 1 c havelow concentration areas 1 b 1 and 1 c 1, with the channel area 1 g inbetween, respectively, and have high concentration areas 1 b 2 and 1 c2, next to the low concentration area 1 b 1 and 1 c 1, respectively. Theconcentration area 1 b 1 and 1 c 1 are positioned between the channelarea 1 g and the high concentration 1 b 2 and between the channel area 1g and the high concentration 1 c 2.

The semiconductor layer 1 a includes, for example, a polycrystallinesilicon film. The gate insulating layer 2 has a two-layer structure.This two-layer structure consists of a first gate insulating layer 2 a,which is a silicon oxide film formed by thermal oxidation of thesemiconductor layer 1 a, and a second gate insulating layer 2 b, whichis a silicon oxide film formed by, for example, the CVD method. The gateelectrode 3 c is formed from a polysilicon film of conductivity, a metalsilicide film, a metal film, or a conductive layer such as a metal filmchemical compound. With the semiconductor layer 1 a in between, the gateelectrode 3 c is electrically connected to the scan line 3 a, throughcontact holes 12 a and 12 b passing through the second gate insulatinglayer 2 b and the insulating layer 12. In the embodiment, the gateelectrode 3 c has a two-layer structure, which consists of a conductivepolysilicon film, approximately 100 nm in thickness and a tungstensilicide film, approximately 100 nm in thickness.

In the embodiment, light reflecting off the other components afterpenetrating the electro-optical device 100 is incident on thesemiconductor layer 1 a, and thus malfunction due to photoelectriccurrent takes place in the pixel transistor 30. In the embodiment, thescan line 3 a is formed like a light shielding film, in order to preventthis. However, the scanning line may be formed on the gate insulatinglayer 2, and one portion of the scanning line may serve as the gateelectrode 3 c. In this case, the scan line 3 a, as shown in FIGS. 3A and3B, is formed for the purpose of light shielding only.

An inter-layer insulating film 41 of translucency, which is made from,for example, a silicon oxide film, is formed on the gate electrode 3 c,in the upward direction, and a data line 6 a and a drain electrode 6 bare formed on an inter-layer insulating film 41, from the same kind ofinsulating film. The inter-layer insulating film 41, for example, ismade from a silicon oxide film formed by a plasma CVD method of usingsilane gas (SH₄) and nitrous oxide (N₂O).

The data line 6 a and the drain electrode 6 b are made from a conductivelayer, such as a conductive polysilicon film, a metal silicide film, ametal film, or a metal film chemical compound. In the embodiment, thedata line 6 a and the drain electrode 6 b have a four-layer structure,which is built by depositing a titanium (Ti) film, 20 nm in thickness,titanium nitride (TiN) film, 50 nm in thickness, aluminum (Al) film, 350nm in thickness, and TiN film, 150 nm in thickness, in this order. Thedata line 6 a is electrically connected to a source area 1 b (a sourcedrain area to the side of the data line) through a contact hole 41 apassing through an inter-layer insulating film 41 and a second gateinsulating layer 2 b. The drain electrode 6 b is formed in such a manneras to partly overlap the drain area 1 c of the semiconductor layer 1 a(a source drain area to the side of the pixel electrode) in an areaoverlapping the first inter-pixel area 10 g, and is electricallyconnected to the drain area 1 c through a contact hole 41 b passingthrough the inter-layer insulating film 41 and the second gateinsulating layer 2 b.

An inter-layer insulating film 42 of translucency, which is made from,for example, the silicon oxide film, is formed on the data line 6 a andthe drain electrode 6 b, in the upward direction. The inter-layerinsulating film 42, for example, is made from the silicon oxide filmformed by, for example, a plasma CVD method of using tetraethoxysilaneand oxygen gas.

The first electrode layer 5 a and the relay electrode 5 b are formed onthe inter-layer insulating film 42 in the upward direction, from thesame kind of insulating film. The first electrode layer 5 a and therelay electrode 5 b are made from a conductive polysilicon film, a metalsilicide film, a metal film, a metal film chemical compound, or others.In the embodiment, the first electrode layer 5 a and the relay electrode5 b have a two-layer structure, which consists of an Al film,approximately 350 nm in thickness and a TiN film, approximately 150 nmin thickness. Like the data line 6 a, the first electrode layer 5 aextends along an area overlapping the second inter-pixel area 10 h. Therelay electrode 5 b is formed in such a manner as to partly overlap adrain electrode 6 b in an area overlapping the first inter-pixel area 10g, and is electrically connected to a drain electrode 6 b through acontact hole 42 a passing through the inter-layer insulating film 42.

An insulating film 44 of translucency (a first insulating film) isformed as an etching stopper layer on the first electrode layer 5 a andthe relay electrode 5 b, in the upward direction, and an opening 44 b isformed in an area overlapping the first electrode layer 5 a on theinsulating film 44. In the embodiment, the insulating film 44 is madefrom, for example, the silicon oxide film formed by, for example, aplasma CVD method of tetraethoxysilane and oxygen gas. At this point,the opening 44 b, not shown in FIG. 3A, is L-shaped, in such a manner asto have a portion extending along an area overlapping the firstinter-pixel area 10 g, starting from an intersection area where the dataline 6 a and the scan line 3 a intersect, and a portion extending alongan area overlapping the second inter-pixel area 10 h, starting from anintersection area where the data line 6 a and the scan line 3 aintersect.

A dielectric layer 40 of translucency is formed on the insulating film44, in the upward direction, and the second electrode layer 7 a isformed on the dielectric layer 40, in the upward direction. The secondelectrode layer 7 a is made from a conductive polysilicon film, a metalsilicide film, a metal film, a metal film chemical compound, or others.In the embodiment, the second electrode layer 7 a is made from a TiNfilm, approximately 300 nm in thickness. Silicon compound, such as asilicon oxide film and a silicon nitride film, may serve as thedielectric layer 40. In addition, a dielectric layer of highconductivity, such as an aluminum oxide film, a titanium oxide film, atantanlum oxide film, a niobium oxide film, a hafnium oxide film, alanthanum oxide film, and a zirconium oxide film, may serve as thedielectric layer 40. The second electrode layer 7 a is L-shaped, in sucha manner as to have a portion extending along an area overlapping thefirst inter-pixel area 10 g, starting from an intersection area wherethe data line 6 a and the scan line 3 a intersect, and a portionextending along an area overlapping the second inter-pixel area 10 h,starting from the intersection area where the data line 6 a and the scanline 3 a intersect. Therefore, in the region of the second electrodelayer 7 a, a portion extending along the area overlapping the secondinter-pixel area 10 h overlaps the first electrode layer 5 a, with thedielectric layer 40 in between, around the opening 44 b in theinsulating film 44. In the embodiment, the first electrode layer 5 a,the dielectric layer 40, and the second electrode layer 7 a make up thestorage capacitance 55 in an area overlapping the first inter-pixel area10 g, in this manner.

Furthermore, in the region of the second electrode layer 7 a, a portionextending along an area overlapping the first inter-pixel area 10 gpartly overlaps the relay electrode 5 b, and is electrically connectedto the relay electrode 5 b through a contact hole 44 a passing throughthe dielectric layer 40 and the insulating film 44.

An inter-layer insulating film 45 of translucency is formed on thesecond electrode layer 7 a, in the upward direction, and the pixelelectrode 9 a, made from a conductive layer of translucency such as anITO film approximately 20 nm in thickness, is formed on the inter-layerinsulating film 45, in the upward direction. The inter-layer insulatingfilm 45, for example, is made from a silicon oxide film formed by, forexample, a plasma CVD method of using tetraethoxysilane and oxygen gas.The pixel electrode 9 a partly overlaps the second electrode layer 7 anear an intersection area where the data line 6 a and scan line 3 aintersect, and pixel electrode 9 a and is electrically connected to thepixel electrode 9 a and the second electrode layer 7 a, in a contactportion 9 t, which is described below.

The oriented film 16 is formed on the surface of the pixel electrode 9a. The oriented film 16 is made from a polymeric film such as polyimide,or from an oblique deposition film such as a silicon oxide film. In theembodiment, the oriented film 16 is an inorganic oriented film (avertical oriented film), made from an oblique deposition film, such asSiO_(X)(x<2), SiO₂, TiO₂, MgO, Al₂O₃, In₂O₃, Sb₂O₃, Ta₂O₅, or others.

In the opposite substrate 20, the common electrode 21, made from aconductive film of translucency such as ITO film, is, in the directionof the liquid crystal layer 50 (in the direction of facing the elementsubstrate 10), formed on the surface of a substrate body 20 w oftranslucency, such as a quartz substrate and a glass substrate, and theoriented film 26 is formed in such a manner as to cover this commonelectrode 21. Like the oriented film 16, the oriented film 26 is madefrom a polymeric film such as polyimide, or from an oblique depositionfilm such as a silicon oxide film. In the embodiment, the oriented film26 is an inorganic oriented film (a vertical oriented film) made fromthe oblique deposition film, such as SiO_(X)(x<2), SiO₂, TiO₂, MgO,Al₂O₃, In₂O₃, Sb₂O₃, Ta₂O₅, or others. These oriented films 16 and 26cause the vertical orientation of nematic liquid crystal compound withnegative dielectric anisotropy in the liquid crystal layer 50, so thatthe liquid crystal panel 100 p operates in the VA mode of normal black.

A complementary transistor circuit, having a re-channel type transistorfor driving and a p-channel type transistor for driving, is included inthe data line drive circuit 101 and the scan line drive circuit 104,above described referring to FIGS. 1 to 2B. At this point, thetransistor for driving may be formed by using process steps ofmanufacturing the pixel transistor 30. For this reason, an area wherethe data line drive circuit 101 and the scan line drive circuit 104 areformed, has the almost same configuration as the cross sectional areashown in FIG. 3B, in the element substrate 10.

Peripheral Configuration of Pixel Electrode 9 a

In the embodiment, a pillar-shaped protrusion 440, protruding toward apixel electrode 9 a, is first formed in a position overlapping the pixelelectrode 9 a in the insulating film 44 (the first insulating film), informing a contact portion 9 t connecting electrically between the pixelelectrode 9 a and the second electrode layer 7 a, in the electro-opticaldevice 100. Furthermore, the second electrode layer 7 a (conductivelayer) is formed in an area overlapping the pillar-shaped protrusion 440in the second electrode layer 7 a. A portion overlapping thepillar-shaped protrusion 440 when viewed from above becomes a conductionsection 7 t connecting electrically to the pixel electrode 9 a. Theinter-layer insulating film 45 (the second insulating film) is formed onthe second electrode layer 7 a, and a surface 7 s of a conductionsection 7 t is exposed on a surface 450 of the inter-layer insulatingfilm 45. Therefore, a pixel electrode 9 a formed on the surface 450 ofthe inter-layer insulating film 45 gets in contact with the surface 7 sof the conduction section 7 t, and thus is electrically connected to thesecond electrode layer 7 a.

At this point, the surface 450 of the inter-layer insulating film 45becomes plane, and thus the surface 450 of the inter-layer insulatingfilm 45 and the surface 7 s of the conduction section 7 t in successionmakes up one plane. For this reason, the pixel electrode 9 a is formedon a plane surface, and thus the surface of the pixel electrode 9 a isplane. Therefore, the oriented film 16 is formed on a plane surface,next to the surface of the pixel electrode 9 a.

In the embodiment, the pillar-shaped protrusion 440 is formed at aposition overlapping the first electrode layer 5 a and the data line 6a, when viewed from above. For this reason, the pillar-shaped protrusion440 is positioned over a film-thick portion of the first electrode layer5 a and the film-thick portion of the data line 6 a.

In the embodiment, the first electrode layer 5 a, to which commonpotential Vcom is applied, and the second electrode layer 7 a, to whichthe potential Vsig is applied, are formed in an area overlapping an area(the second inter-pixel area 10 h) between the pixel electrodes 9 aadjacent in the first direction (in the X direction), but the secondelectrode layer 7 a is positioned over the first electrode layer 5 a (tothe side of the pixel electrode 9 a), in the upward direction. At thispoint, the potential Vsig applied to the second electrode layer 7 a isthe same as that applied to the pixel electrode 9 a. The scan line 3 a,to which the scan signal is applied, and the second electrode layer 7 a,to which the potential Vsig is applied, are formed in an areaoverlapping an area (the first inter-pixel area 10 g) between the pixelelectrodes 9 a adjacent in the second direction (in the Y direction),but the second electrode layer 7 a is positioned over the scan line 3 a(to the side of the pixel electrode 9 a) in the upward direction. Atthis point, the potential Vsig applied to the second electrode layer 7 ais the same as that applied to the pixel electrode 9 a.

Manufacturing Method of the Electro-Optical Device 100

FIGS. 4A to 5E are explanatory views of showing the essential steps of amanufacturing process of the electro-optical device 100 to which theaspect of the invention is applied. The steps are actually performed ona large-sized substrate which is to be divided into a plurality ofelement substrates 10 in the subsequent step, but is below described interms of the element substrate 10 regardless of the size of thesubstrate. Furthermore, the proceeding steps of forming the firstelectrode layer 5 a are well known in the art and therefore are notdescribed below.

In the manufacturing process of the electro-optical device 100 accordingto the embodiment, in the step of forming the element substrate 10, theinsulating film 44 (the first insulating film) is formed from a siliconoxide film, approximately 600 nm in thickness by, for example, a plasmaCVD method of tetraethoxysilane and oxygen gas, in the step of formingthe first insulating film, after the first electrode layer 5 a and therelay electrode 5 b are formed by a well-known method as shown in FIG.4A. The first electrode layer 5 a has a two-layer structure, whichconsists of an Al film, approximately 350 nm in thickness and a Tinfilm, approximately 150 nm in thickness.

Next, a mask 44 r is formed in a position overlapping an area where thepixel electrode 9 a needs to be formed, and, under this condition, thesurface of the insulating film 44 is etched, in the insulating film 44in a step of forming the pillar-shaped protrusion as shown in FIG. 4B.As a result, the pillar-shaped protrusion 440, protruding upward, isformed on the insulating film 44. This etching may be performed by a RIE(reactive ion etching) method of using fluorine-series gas such as CF₄(tetrafluoromethane) and CHF₃ (methane trifluoride), and therefore ishigh in etching anisotropy. In addition, the etching ensures easycontrol of an amount of etching. Therefore, the pillar-shaped protrusion440 may be formed on the insulating film 44, in an easy manner andwithout any failure.

Next, in a step of forming an opening, as shown in FIG. 4C, a mask 44 s,for making an opening in an area where the opening 44 b needs to beformed, is formed on the surface of the insulating film 44, and, underthis condition, the opening 44 b is formed by etching the insulatingfilm 44.

Next, as shown in FIG. 4D, a dielectric layer 40 is formed on theinsulating film 44, in the upward direction, in a step of forming adielectric layer.

Next, in a step of forming a contact hole, as shown in FIG. 4E, a mask44 t, for making an opening in an area where a contact hole 44 a needsto be formed, is formed on the surface of the dielectric layer 40, and,under this condition, the contact hole 44 a is formed in a positionoverlapping the relay electrode 5 b by etching the dielectric layer 40and the insulating film 44.

Next, as shown in FIG. 5A, a mask 7 r is formed in an area where thesecond electrode layer 7 a needs to be formed, and, under thiscondition, the second electrode layer 7 a is formed by etching thedielectric layer 40 and the conductive layer 7, after a conductive layer7 was formed on the surface of the dielectric layer 40 in a step offorming a conductive layer, as shown in FIG. 4F. At this point, aportion overlapping the highest surface of the pillar-shaped protrusion440 in the second electrode layer 7 a becomes a conduction section 7 t,when this step is performed, the insulating film 44 exists as an etchingstopper layer, in a position overlapping the highest portion of thesecond electrode layer 7 a. For this reason, short circuit between thefirst electrode layer 5 a and the second electrode layer 7 a may beprevented by the insulating film 44, although the dielectric layer 40 isthin. In the embodiment, the second electrode layer 7 a, is made from,for example, a TiN film, approximately 300 nm in thickness.

Next, in a step of forming a second insulating film, as shown in FIG.5B, the inter-layer insulating film 45 (the second insulating film) isformed from a silicon oxide film, approximately 2000 nm in thickness, bya plasma CVD method of using tetraethoxysilane and oxygen gas.

Next, in a step of exposing a conduction section, as shown in FIG. 5C,the surface 7 s of the conduction section 7 t of the second electrodelayer 7 a is exposed by removing the inter-layer insulating film 45 fromthe surface 450. In this step of exposing the conduction section, forexample, a surface of the inter-layer insulating film 45 is polished. Inthis polishing step, chemical mechanical polishing may be performed, andthus, a smooth polished surface may be accomplished at high speed byaction of chemical composition contained polishing liquid and by therelative movement between a polishing agent and the element substrate10. More specifically, polishing apparatus performs polishing byproducing the relative movement between a surface plate to which apolishing cloth (a pad) is attached, and a holder holding the elementsubstrate 10. The polishing cloth may be made from non-woven fabric,foamed polyurethane, porous fluorocarbon resin, and other materials. Atthis point, for example, a polishing agent is provided between thepolishing cloth and the element substrate 10. The polishing agentincludes a cerium oxide particle with an average diameter of 0.01 μm to20 μm, acrylic acid ester derivative as a dispersing agent, and water.As a result, the surface 450 of the inter-layer insulating film 45becomes plane, and is at the same level as the surface 7 s of theconduction section 7 t.

Furthermore, a so-called etch back method may be alternatively used inremoving the inter-layer insulating film 45 from the surface 450 in thedownward direction to expose the surface 7 s of the conduction section 7t of the second electrode layer 7 a. In this etch back method, dryetching is performed on a resin layer and the inter-layer insulatingfilm 45 at the same speed, until the surface 7 s of the conductionsection 7 t is exposed, after forming the resin layer on the surface ofthe inter-layer insulating film 45.

Next, in a step of forming a pixel electrode, a mask 9 r, as shown inFIG. 5E, is formed in an area where a pixel electrode 9 a needs to beformed, and, under this condition, the pixel electrode 9 a is formed byetching a conductive film 9 for the pixel electrode, after forming theconductive film 9 for the pixel electrode, such as an ITO film,approximately 20 nm in thickness, on the surface of the inter-layerinsulating film 45, by using, for example, the sputtering method, asshown in FIG. 5D. As a result, the pixel electrode 9 a comes in contactwith the surface 7 s of the conduction section 7 t of the secondelectrode layer 7 a, and thus is electrically connected to the secondelectrode layer 7 a.

Thereafter, an oriented film 16 is formed as shown in FIGS. 3A and 3B.Subsequent steps are performed by using well-known methods and thereforeare not described.

Main Effects of the Embodiment

As is above described, in the electro-optical device 100 and themanufacturing method of the electro-optical device 100 according to theembodiment, the pillar-shaped protrusion 440, protruding at the positionoverlapping the pixel electrode 9 a toward the pixel electrode 9 a, isformed on the insulating film 44 (the first insulating film) providedbelow the pixel electrode 9 a (between the pixel electrode 9 a and thesubstrate body 10 w), in the downward direction, and thus the conductionsection 7 t of the second electrode layer 7 a (the conductive layer)overlaps the highest surface of this pillar-shaped protrusion 440.Furthermore, the inter-layer insulating film 45 (the second insulatingfilm) is provided between the second electrode layer 7 a and the pixelelectrode 9 a, but the conduction section 7 t is exposed on the surface450 of the inter-layer insulating film 45. For this reason, the pixelelectrode 9 a is electrically connected to the conduction section 7 t,when the pixel electrode 9 a is deposited on the inter-layer insulatingfilm 45. For this reason, the contact portion is smaller in horizontalsize, the pixel electrode does 9 a does not have a large depression andelevation on the surface, compared to the structure that connects thepixel electrode and the conductive layer by using the contact holeformed in the insulating film. Furthermore, conduction of the pixelelectrode 9 a may be done by using the film formed in theelectro-optical device 100 for other purposes, such as the secondelectrode layer 7 a, the insulating film (the insulating film 44 and theinter-layer insulating film 45), and others. That is, conduction of thepixel electrode 9 a may be done by using the insulating film 44 thatfunctions as the etching stopper layer, and the second electrode layer 7a making up the storage capacitance 55. Therefore, in the embodiment,there is no need to deposit thickly a special thick metal for the plug.

Furthermore, in the embodiment, the pixel electrode 9 a may be formed onthe plane surface, since the surface 7 s of the conduction section 7 tand the surface 450 of the inter-layer insulating film 45, which adjoineach other in succession, are at the same level. Therefore, the surfaceof the pixel electrode 9 a is made to be plane. Therefore, the orientedfilm 16 may be formed on the plane surface of the pixel electrode 9 a,and thus the oriented film 16 may be formed in a suitable manner.Furthermore, the pillar-shaped protrusion 440 is formed at the positionoverlapping the first electrode layer 5 a and the data line 6 a, whenviewed from above. For this reason, since the pillar-shaped protrusion440 is positioned over the film-thick portion of the first electrodelayer 5 a and the film-thick portion of the data line 6 a, theconduction section 7 t is easy to expose on the surface of theinter-layer insulating film 45. This provides a condition suitable forthe formation of the contact portion 9 t of the pixel electrode 9 a.

Other Effects of the Embodiment

FIGS. 6A and 6B are explanatory views showing the effects of theelectro-optical device 100 to which the aspect of the invention isapplied. FIG. 6A is a schematic configuration of the pixel electrodes inthe electro-optical device 100. FIG. 6B is a schematic configuration ofthe pixel electrodes in the comparative example.

As shown in FIGS. 3A, 3B, in the electro-optical device 100 according tothe embodiment, the second electrode layer 7 a (the conductive layer)and the first electrode layer 5 a (the capacity electrode layer) areprovided in an area overlapping the area (the second inter-pixel area 10f) between the pixel electrodes 9 a adjacent in the X direction.However, as shown in FIG. 6A, in this embodiment, the second electrodelayer 7 a is positioned over the first electrode layer 5 a in the upwarddirection (near the pixel electrode 9 a). For this reason, theorientation of the liquid crystal layer 50 is not disturbed by electricpotential occurring between the pixel electrode 9 a and the firstelectrode layer 5 a.

More specifically, as shown in FIGS. 6A and 6B, in the electro-opticaldevice 100, the orientation of liquid crystal molecules of the liquidcrystal layer 50 is controlled by a longitudinal electric field(indicated by an arrow V1) between the pixel electrode 9 a in theelement substrate 10 and the common electrode 21 to which the commonpotential Vcom is applied in the opposite substrate 20, and opticalmodulation is performed on each pixel. At this point, the commonpotential Vcom is applied to the first electrode layer 5 a and thepotential Vsig is applied to the second electrode layer 7 a. Thepotential Vsig applied to the second electrode layer 7 a is the same asthat applied to the pixel electrode 9 a. For this reason, as is shown inthe comparative example of FIG. 6B, when the first electrode layer 5 ais positioned over second electrode layer 7 a in the upward direction(near the pixel electrode 9 a), an unnecessary electric field (indicatedby an arrow V2) occurs between the highest portion of the pixelelectrode 9 a and the first electrode layer 5 a, and thus disturbance ofpotential distribution occurs near the highest portion of the pixelelectrode 9 a.

In contrast, in the embodiment, the second electrode layer 7 a ispositioned over the first electrode layer 5 a in the upward direction(near the pixel electrode 9 a). Since the unnecessary electric field,indicated by the arrow V2, does not occur for this reason, thedisturbance of the potential distribution does not occur near thehighest portion of the pixel electrode 9 a, and thus the distribution ofliquid crystal molecules may be controlled even near the highest portionof the pixel electrode 9 a, in a suitable manner. Even though anelectric field occurs in an area between the pixel electrode 9 a and thesecond electrode layer 7 a (the area is positioned near the pixelelectrode 9 a), this electric field does not cause critical effects,because potential difference is small, compared to the potential (commonpotential Vcom) applied to the first electrode layer 5 a.

Other Embodiments

In the embodiment, the example is above described in which the aspect ofthe invention is applied to the transmission-type electro-optical device100, but the aspect of the invention may be applied to thereflection-type electro-optical device 100.

Furthermore, the example is described in which the aspect of theinvention is applied to the electro-optical device 100, but the aspectof the invention may be applied to other electro-optical devices, suchas an organic electroluminescence device.

Example of Equipping Electronic Device with Electro-Optical Device

Configuration Example of Projection-Type Display Device and Optical Unit

FIGS. 7A and 7B are schematic configurations of a projection-typedisplay device to which the aspect of the invention is applied and anoptical unit. FIG. 7A is a schematic configuration of theprojection-type display device using the transmission-typeelectro-optical device. FIG. 7B is a schematic configuration of theprojection-type display device using the reflection-type electro-opticaldevice.

A projection-type display device 110, as shown in FIG. 7A, is an exampleof using a transmission-type liquid crystal panel as a liquid crystalpanel. In contrast, the projection-type display device 1000, as shown inFIG. 7B, is an example of using the reflection-type liquid crystal panelas a liquid crystal panel. However, as is below described, theprojection-type display device 110 includes a light source unit 130, aplurality of electro-optical devices 100 receiving light of differentwavelength regions from the light source unit 130, a cross dichroicprism 119 (an optical system of photosynthesis) synthesizing andemitting the light from the plurality of the electro-optical devices100, and a projection optical system 118 projecting the lightsynthesized by the cross dichroic prism 119. Likewise, a projection-typedisplay device 1000 includes a light source unit 1021, a plurality ofelectro-optical devices 100 receiving light of different wavelengthregions from the light source unit 1021, a cross dichroic prism 1027(the optical system of photosynthesis) synthesizing and emitting thelight from the plurality of the electro-optical devices 100, and aprojection optical system 1029 projecting the light synthesized by thecross dichroic prism 1027. Furthermore, an optical unit 200, includingthe electro-optical device 100 and the cross dichroic prism 119 (theoptical system of photosynthesis), is used in the projection-typedisplay device 110. Likewise, an optical 200, including theelectro-optical device 100 and the cross dichroic prism 1027 (theoptical system of photosynthesis), is used in the projection-typedisplay device 1000.

First Example of Projection-Type Display Device

The projection-type display device 110, as shown in FIG. 7A, projectslight onto a screen 111 prepared by a viewer, and the viewer sees thelight reflected by the screen 111. The projection-type display device110 is a so-called screen-reflected type. The projection-type displaydevice 110 includes a light source unit 130 including a light source112, dichroic mirrors 113 and 114, liquid crystal light valves 115, 116,and 117, a projection optical system 118, a cross dichroic prism 119(the optical system of photosynthesis), and a relay system 120.

The light source 112 includes an extra-high pressure mercury lampsupplying light including red light R, green light G, and blue light B.The dichroic mirror 113 has a configuration that allows red light R fromthe light source 112 to penetrate, but reflects green light G and bluelight B from the light source 112. Furthermore, the dichroic mirror 114has a configuration that allows blue light B, reflected by the dichroicmirror 113, to penetrate, but reflects green light G, reflected by thedichroic mirror 113. In this way, the dichroic mirrors 113 and 114 makeup a color separation optical system that separates light emitted fromthe light source 112 into red light R, green light G, and blue light B.

At this point, an integrator 121 and a polarization conversion element122 are arranged in this order from the light source 112 between thedichroic mirror 113 and the light source 112. The integrator 121 has aconfiguration that makes uniform the illumination distribution of lightemitted from the light source 112. Furthermore, the polarizationconversion element 122 has a configuration that converts light emittedfrom the light source 112 into polarized light having a specificvibration direction, such as s polarized light.

The liquid crystal light valve 115 is a transmission-typeelectro-optical device that modulates red light R that penetrates thedichroic mirror 113, but reflects off a reflecting mirror 123, inresponse to an image signal. The liquid crystal light valve 115 includesa λ/2 phase difference plate 115 a, a first polarizing plate 115 b, theelectro-optical device 100 (a liquid crystal panel 100R for red), and asecond polarization 115 d. At this point, the red light R that isincident on the liquid crystal light valve 115 does not experience anychange in polarized light and therefore maintains s polarized light eventhough the red light R penetrated the dichroic mirror 113.

The λ/2 phase difference plate 115 a is an optical element that convertss polarized light, that is incident on the liquid crystal light valve115, into p polarized light. Furthermore, the first polarizing plate 115b is a polarizing plate that blocks s polarized light and allows ppolarized light to penetrate. The electro-optical device 100 (a liquidcrystal panel 100R for red) has a configuration that converts ppolarized light into s polarized light (circularly polarized light orelliptically polarized light in the case of a half tone), by modulationthat is in response to the image signal. In addition, the secondpolarizing plate 115 d is a polarizing plate that blocks p polarizedlight and allows s polarized light to penetrate. Therefore, the liquidcrystal light valve 115 has a configuration that modulates red light Rin response to the image signal, and emits the modulated red light Rtoward the cross dichroic prism 119.

The λ/2 phase difference plate 115 a and the first polarizing plate 115b is arranged in such a manner as to be in contact with a glass plate115 e of translucency that does not convert polarized light, andtherefore the λ/2 phase difference plate 115 a and the first polarizingplate 115 b may be prevented from warping due to generated heat.

The liquid crystal light valve 116 is a transmission-typeelectro-optical device that modulates green light G that reflected offthe dichroic mirror 114 after reflecting off the dichroic mirror 113, inresponse to the image signal. The liquid crystal light valve 116, likethe liquid crystal light valve 115, includes a first polarizing plate116 b, the electro-optical device 100 (a liquid crystal panel 100G forgreen), and a second polarizing plate 116 d. The green light G that isincident on the liquid crystal light valve 116, is s polarized lightthat reflected off the dichroic mirrors 113 and 114. The firstpolarizing plate 116 b is a polarizing plate that blocks p polarizedlight and allows s polarized light to penetrate. Furthermore, theelectro-optical device 100 (the liquid crystal panel 100G for green) hasa configuration that converts s polarized light into p polarized light(circularly polarized light, or elliptically polarized light in a caseof a half tune) by modulation that is in response to the image signal.The second polarizing plate 116 d is a polarizing plate that blocks spolarized light and allows p polarized light to penetrate. Therefore,the liquid crystal light valve 116 has a configuration that modulatesgreen light G in response to the image signal, and emits the modulatedgreen light G toward the cross dichroic prism 119.

The liquid crystal light valve 117 is a transmission-typeelectro-optical device that modulates blue light B that reflected offthe dichroic mirror 113, penetrated the dichroic mirror 114, and thenpassed through the relay system 120, in response to the image signal.The liquid light valve 117, like the liquid crystal light valves 115 and116, includes a λ/2 phase difference plate 117 a, a first polarizingplate 117 b, the electro-optical device 100 (a liquid crystal panel 100Bfor blue), and a second polarizing plate 117 d. At this point, the bluelight B that is incident on the liquid light valve 117 becomes spolarized light, because the blue light B that reflected off thedichroic mirror 113 and penetrated the dichroic mirror 114 reflects offtwo reflecting mirrors 125 a and 125 b, which are described below, ofthe relay system 120.

The λ/2 phase difference plate 117 a is an optical element that convertss polarized light that was incident on the liquid light valve 117, intop polarized light. Furthermore, the first polarizing plate 117 b is apolarizing plate that blocks s polarized light and allows p polarizedlight to penetrate. The electro-optical device 100 (the liquid crystalpanel 100B for blue) has a configuration that converts p polarized lightinto s polarized light (circularly polarized light, or ellipticallypolarized light in a case of a half tune) by modulating p polarizedlight in response to the image signal. In addition, the secondpolarizing plate 117 d is a polarizing plate that blocks p polarizedlight and allows s polarized light to penetrate. Therefore, the liquidcrystal light valve 117 has a configuration that modulates blue light Bin response to the image signal, and emits the modulated blue light Btoward the cross dichroic prism 119. The λ/2 phase difference plate 117a and the first polarizing plate 117 b are arranged in such a manner asto be in contact with the glass plate 117 e.

The relay system 120 includes relay lenses 124 a and 124 b, andreflecting mirrors 125 a and 125 b. The relay lenses 124 a and 124 b areprovided to prevent optical loss that is due to a long optical path ofblue light B. At this point, the relay lens 124 a is arranged betweenthe dichroic mirror 114 and the reflecting mirror 125 a. Furthermore,the relay lens 124 b is arranged between the reflecting mirrors 125 aand 125 b. The reflecting mirror 125 a is arranged in such a manner asto reflect blue light B that penetrated the dichroic mirror 114 and wasemitted from the relay lens 124 a, toward the relay lens 124 b.Furthermore, the reflecting mirror 125 b is arranged in such a manner asto reflect blue light B that was emitted from the relay lens 124 b,toward the liquid light valve 117.

The cross dichroic prism 119 is an optical system of color synthesis, inwhich the two dichroic films 119 a and 119 b cross at a right angle inan X shape. The dichroic film 119 a reflects blue light B and allowsgreen light G to penetrate. The dichroic film 119 b reflects red light Rand allows green light G to penetrate. Therefore, the cross dichroicprism 119 has a configuration that synthesizes red light R, green lightG, and blue light B modulated in the liquid crystal light valves 115,116, 117, respectively, and emits the synthesized red light R, greenlight G, and blue light B toward the projection optical system 118.

Light which is incident on the cross dichroic prism 119 from the liquidcrystal light valves 115 and 117 is s polarized light, and light is ppolarized light which is incident on the cross dichroic prism 119 fromthe liquid crystal light valve 116 is p polarized light. Light that isincident on the cross dichroic prism 119 is made to be different kindsof polarized light in this way, and thus light emitted from the liquidcrystal light valves 115, 116, and 117 may be synthesized in the crossdichroic prism 119. Generally, each of the dichroic films 119 a and 119b have excellent reflection transistor characteristic of s polarizedlight. For this reason, red light R and blue light B that is reflectedby the dichroic films 119 a and 119 b is determined as s polarizedlight, and green light G that penetrates the dichroic films 119 a and119 b is determined as p polarized light. The projection optical system118 has a configuration that includes a projection lens (not shown) andprojects light synthesized by the cross dichroic prism 119 onto thescreen 111.

Second Example of Projection-Type Display Device

The projection-type display device 1000, as shown in FIG. 7B, includes alight source unit 1021 generating light source light, a color separationlight guide optical system 1023 separating the light source lightemitted from the light source unit 1021 into 3 color light of red lightR, green light G, and blue light B, and a light modulating unit 1025that is illuminated by each light source light emitted from the colorseparation light guide optical system 1023. Furthermore, theprojection-type display device 1000 includes a cross dichroic prism 1027(the optical system of photosynthesis) synthesizing image light emittedfrom the light modulating unit 1025, and a projection optical system1029 projecting the image light passing through the cross dichroic prism1027 onto a screen (not shown).

In this projection-type display device 1000, the light source unit 1021includes a light source 1021 a, a pair of fly eye optical systems 1021 dand 1021 e, a polarized light conversion member 1021 g and asuperimposing lens 1021 i. In the embodiment, the light source unit 1021includes a reflector 1021 f with paraboloid surface and emits parallellight. Each of the fly eye optical systems 1021 d and 1021 e is made upof a plurality of element lens arranged in the matrix on the surfaceintersecting a system optical axis. Light-source light is separated bythe plurality of the element lens, and then is individually concentratedand radiated. The polarized light conversion member 1021 g converts thelight-source light emitted from the fly eye optical system 1021 e into ap polarized light component only, for example, in parallel with thedrawing, and supply the p polarized light component to the opticalsystem, down the optical path. The superimposing lens 1021 i enableseach of the electro-optical devices 100, provided in the lightmodulating unit 1025, to perform superimposed lighting in a uniformmanner, by converging properly the light-source light, as a whole, thatpassed through the polarized light conversion member 1021 g.

The color separation light guide optical system 1023, includes a crossdichroic mirror 1023 a, a dichroic mirror 1023 b, and reflection mirrors1023 j and 1023 k. In the color separation light guide optical system1023, almost white light-source light from the light source unit 1021 isincident on the cross dichroic mirror 1023 a. The red light R, reflectedby the first dichroic mirror 1031 a, as one element making up the crossdichroic mirror 1023 a, reflects off the reflection mirror 1023 j,penetrates the dichroic mirror 1023 b. Then, the red light R, polarizedlight as it is, is incident on the electro-optical device 100 (a liquidcrystal panel 100R for red), through a polarizing plate 1037 r, which isopposite to incident light, a wire grid polarizing plate 1032 r, whichallows p polarized light to penetrate, but reflects s polarized light,and an optical compensation plate 1039 r.

Furthermore, the green light G, reflected by the first dichroic mirror1031 a, reflects off the reflection mirror 1023 j, and then reflects offthe dichroic mirror 1023 b as well. Then, the green light G, remainingas p polarized light, is incident on the electro-optical device 100 (aliquid crystal panel 100G for green), through a polarized plate 1037 g,which is opposite to incident light, a wire grid polarizing plate 1032g, which allows p polarized light to penetrate, but reflects s polarizedlight, and an optical compensation plate 1039 g.

In contrast, the blue light B, reflected by the second dichroic mirror1031 b, as the other element making up the cross dichroic mirror 1023 a,reflects off the reflection mirror 1023 k. Then, the blue light B isincident on the electro-optical device 100 (the liquid crystal panel100B for blue), through a polarizing plate 1037 b, which is opposite toincident light, a wire grid polarizing plate 1032 b, which allows ppolarized light to penetrate, but reflects s polarized light, and anoptical compensation plate 1039 b. The optical compensation plates 1039r, 1039 g, and 1039 b enhance the characteristics of the liquid crystallayer in a compensating manner, by controlling the incident light thatis incident on the electro-optical device 100 and the polarized state ofemitted light, in an optical manner.

In the projection-type display device 1000 with this configuration, eachof light of 3 colors, incident after passing through the opticalcompensation plates 1039 r, 1039 g, and 1039 b, is modulated in thecorresponding electro-optical device 100. At this point, among modulatedlight emitted from the electro-optical device 100, component light of spolarized light reflects off the wire grid polarizing plates 1032 r,1032 g, and 1032 b, and is incident on the cross dichroic prism 1027,through emitting-side polarizing plates 1038 r, 1038 g, and 1038 b. Afirst dielectric multi-layered film 1027 a and a second dielectricmulti-layered film 1027 b, which intersect in an X shape, are formed inan X shape on the cross dichroic prism 1027. The first dielectricmulti-layered film 1027 a on one side reflects red light R, and thesecond dielectric multi-layered film 1027 b on the other side reflectsblue light B. Therefore, light of 3 colors is synthesized in the crossdichroic prism 1027, and is emitted to the projection optical system1029. Then, the projection optical system 1029 projects image light ofcolor synthesized in the cross dichroic prism 1027 on a given scale ontothe screen (not shown).

Other Projection-Type Display Devices

The projection-type display device may use an LED light source emittingeach light of color as the light source unit, and have a configurationthat provides light of color emitted from this LED light source for aseparate liquid crystal device.

Other Electronic Devices

The electro-optical device 100 to which the aspect of the invention isapplied, may serve as a direct-view display device for an electronicdevice, such as a portable telephone, a PDA (Personal DigitalAssistants), a digital camera, a liquid crystal television, a carnavigation device, a television telephone, a POS terminal, a deviceequipped with a touch panel, and others.

What is claimed is:
 1. An electro-optical device comprising: a pixelelectrode provided over one side of a substrate; a conductive layerprovided between the substrate and the pixel electrode; a relayelectrode provided between the substrate and the conductive layer;wherein the conductive layer includes a first conduction sectionprotruding toward the pixel electrode and a second conduction sectionprotruding toward the relay electrode, the first conduction section iscylindrical-shaped having an upper surface which is attached to thepixel electrode, and having a side surface sloping from the uppersurface, and the pixel electrode is electrically connected to the relayelectrode through the conductive layer.
 2. The electro-optical deviceaccording to claim 1, wherein the second conduction section iscylindrical-shaped.
 3. The electro-optical device according to claim 1,wherein a surface of the first conduction section and a surface of thesecond conduction section make up a continuous surface.
 4. Aprojection-type display device comprising: the electro-optical deviceaccording to claim 1; a light source unit emitting light to be incidenton the electro-optical device; and a projection optical systemprojecting light modulated by the electro-optical device.
 5. Anelectronic device comprising the electro-optical device according toclaim
 1. 6. An electro-optical device comprising: a pixel electrodeprovided over one side of a substrate; a conductive layer providedbetween the substrate and the pixel electrode, the conductive layerincluding a conduction section protruding toward the pixel electrode; arelay electrode provided between the substrate and the conductive layer;a first insulating film provided between the substrate and the pixelelectrode, the first insulating film having a protrusion protrudingtoward the pixel electrode and an opening overlapping the relayelectrode; and a second insulating film provided between the conductivelayer and the pixel electrode; wherein the pixel electrode iselectrically connected to the conduction section, and the conductionsection is electrically connected to the relay electrode, and a surfaceof the conduction section facing the pixel electrode and a surface ofthe second insulating film facing the pixel electrode make up acontinuous surface.
 7. An electro-optical device comprising: a pixelelectrode provided over one side of a substrate; a conductive layerprovided between the substrate and the pixel electrode, the conductivelayer including a first conduction section protruding toward the pixelelectrode and a second conduction section protruding toward thesubstrate; and a relay electrode provided between the substrate and theconductive layer; wherein the first conduction section has an uppersurface farthest away from the substrate, and a side surface slopingfrom the upper surface toward the substrate, and the pixel electrodecontacts the upper surface of the first conduction section and iselectrically connected to the relay electrode through the firstconduction section and the second conduction section.